Lange volumes of biodegradable materials are accumulated in landfills and solid waste disposal sites throughout the world. Solid waste disposal sites near many urban regions literally have generated mountains at locations that once had been flat marshlands. While urban areas are choking with accumulated solid wastes, most countries are experiencing an energy shortfall. Thus, many countries, including the United States, generate more solid waste than the population can conveniently process, and simultaneously consume more energy than the country can produce.
In recent years many government agencies have attempted to capitalize on the known fact that the decaying biodegradable materials in solid waste disposal sites will generate methane gas that can be used as a fuel in power generators and in some vehicles. Thus, the objectionable landfills and solid waste disposal sites can be used positively to meet energy needs.
The methane gas generated in landfills and solid waste disposal sites can be accessed only by providing below grade pipe systems in the landfill for tapping and controlling the flow of methane gas. In some instances the pipe systems for tapping the methane gas can be installed at a below grade location in an established landfill or solid waste disposal site. More desirably, however, pipe systems will be laid prior to depositing the solid waste or fill. It has been found extremely desirable to employ thermoplastic pipes, valves and fittings in view of their superior resistance to moisture and the corrosive materials present in the landfills or solid waste disposal sites.
The piping systems required to tap the methane gas in a landfill or solid waste disposal site will often be disposed 10-50 feet below grade. Even though the valves incorporated into such a system may be electrically operated, it will be necessary for the valve stems to be accessible from an at grade location. Thus, the valves incorporated into such systems may have extended valve stems of 10-50 feet in length. Furthermore, the length of a valve stem may require periodic extensions as the landfill is accumulating. For example, a valve stem may initially be approximately ten feet long, but may ultimately reach a length of forty or fifty feet.
The valve stem is connected to a valve member movably disposed within a valve housing to alternately open or block a flow passage in the valve. The valves used in this environment may be ball valves, gate valves, butterfly valves, or diaphragm valves. The valving member is subjected to considerable pressure by the gas or fluid flowing through the system. As a result, it is necessary for a valve stem to be very strong to transmit the necessary torque to the valve member. This necessarily requires the valve stem to be of considerable weight. As the length of the valve stem is extended to 10-50 feet for use in the above described landfills and solid waste disposal sites, the weight of the valve stem becomes very significant and can affect the operation of the valve. In particular, the weight of a long valve stem creates loads that can break or deform portions of a valve or can significantly impede efficient operation of the valve.
In view of the above, it is an object of the subject invention to provide an efficient valve system for use in landfills and solid waste disposal sites.
It is another object of the subject invention to provide a valve having an elongated valve stem extension operatively connected to the valve.
An additional object of the subject invention is to provide a support system for supporting an elongated heavy valve stem.
Yet another object of the subject invention is to provide a valve stem assembly that ensures efficient operation of a valve despite the use of a long heavy valve stem.